Computer expert needed asap

Our desktop computer won't connect to the internet. At first it wouldn't connect at all. It would just say "Limited or no Connection". Then we hooked it up to a router and it says it is connected, but we still can't browse the web.

I googled this and spent 3-4 hours today trying every possible thing that I could find, but nothing has helped. Just a few days ago we had the DSL cable plugged directly into the back of the computer and everything was fine. Then that stopped working so we hooked it up to the router. And as I said, it now says that it is connected, but when the internet is opened it does the dreaded "Page cannot be displayed..." For the record I'm posting this from my laptop, which is wireless, and connects fine, as does my moms laptop. But the two laptops go through a different router and DSL cable than the desktop does. Some one please help me!

Eh whenever something like this happens i usually just unplug ALL electrical outlets and internet cables, even the computer one, and wait about 2-3mins, then plug everything back in and reboot and this works about 50% of the time.

Right click on the LAN icon or Wireless icon, whichever you are using to connect, and go to status. In that window open the tab support and then press the button details. The Address Type should be Assigned by DHCP. If it is then there is another problem with the router itself and I can get into that later if need be. If it is not and it says something like Manually Assigned then you can go back to the General tab and click on properties. Another window will open. Scroll down to Internet Protocol (TCP/IP) and click on it once, then click properties. Click on Obtain an IP Address automatically and lower down click Obtain DNS server address automatically. Let me know how that goes.

like mentioned above it sounds like your modem died, happened to me a little while back, sounds exactly same.
also dsl companies usually require a login to access the interent, if so how that could have been changed on the modem or on your computer then that could be causing the problem
if the computer is telling you that there is a cable plugged in then it has nothing to do with any hardware, if you have tried to reset the password and such it is time to contact the isp